DESCRIPTION (provided by candidate): Psychopathy is a serious personality disorder with interpersonal, affective, and behavioral components. One hallmark of psychopathy is the persistent violation of social contracts, i.e., cheating. In a cooperative species such as humans, the societal costs of this behavior are tremendous. Indeed, the frequency and extent of (normal) humans'cooperation is astounding compared to the rest of the animal kingdom. Evolutionary analyses have identified several cognitive abilities necessary for cooperation to evolve, including the ability to detect cheaters. A large body of data has demonstrated that normal individuals are adept at detecting cheaters when reasoning about social exchange, and evidence about which brain regions underlie this ability has begun to accrue. Both the behavioral and neural data indicate that social exchange reasoning is functionally distinct from other types of reasoning (e.g., precautionary reasoning). The goal of the proposed research is to investigate social exchange reasoning in psychopathy. Specifically, the aim is to address the following questions: Is reasoning about social exchange (i.e., cheater detection) impaired in psychopathy? Do psychopaths recruit the same brain regions to reason about social exchange that normal, healthy individuals do? Does social exchange reasoning show the same relationship with emotional intelligence in psychopaths as it does in normal individuals? The proposed studies employ event-related functional magnetic resonance imaging to investigate the behavioral performance and brain basis of incarcerated psychopaths'and control participants'reasoning about social exchange, precautionary, and social descriptive rules, using the Wason selection task. Including these two types of rules will allow us to investigate the specificity of the results to social exchange. Normal individuals perform equally well on social exchange and precautionary rules;psychopaths are high risk-takers,suggesting precautionary reasoning will be informative. Social descriptive rules are also social in nature, but fail to fit the input conditions for social exchange rules;normal individuals are very sensitive to this distinction. The Wason selections task is ideal for imaging studies in that the three types of reasoning problems differ only in their content-the task demands are identical across problem type.